Stick to the dealer for parts when dealing with overheating.

[jbeckford]

I just want to share my car overheating journey and hopefully have others learn from my experience.

Long Story Short:
The dealer part that was only $20 more than some off brand after market piece ($80 vs $60) would have saved me lots of time and frustration, not to mention the risk of severe damage to my car.

The Details:
My 2006 Infiniti M35 was overheating.
I noticed the passenger side fan was not spinning even though the a/c was on.
I gave the fan a flick with my finger to get it spinning and the fan successfully spun.
I determined that the fan motor was bad.
I looked into replacing the motor alone, but had no luck and had to replace the whole fan assembly (2 fans with a fan control module mounted on a frame.)
I swapped the fan assembly out , replacing the OEM one with:
TYC 621870 Infiniti Replacement Radiator/Condenser Cooling Fan Assembly
Both fans seemed to be working properly.
I did this late summer and didn't really drive the car much since I commute via mass transit to work.
I had no problems throughout the fall and winter.
Come summer, my car started overheating.
I checked the fans and they were spinning but the condenser side fan seemed like it was oscillating and not spinning at high speed even when the car was hot.
I decided to replace the fan control module over my now 9 month old purchase TYC 621870 fan.
I replaced the fan control module and the car was ok for a bit but a month later I realized that it was overheating.
The condenser fan was oscillating again and would often stop.
I bled and burped my coolant system several times, per the recommendation from many people addressing overheating Infiniti's.
The car continued to overheat.
I changed the thermostat with an OEM thermostat from the dealership, figuring perhaps the thermostat is not letting coolants circulate and hit the coolant temperature sensor. (I was reaching at this point.)
The car continued to overheat.
I checked the motors on the fan independently from the fan control module and they both worked fine, getting up to high speed.
When the car was hot and the fan was not running, I checked the output PWM duty cycle from the fan module to the motor with a multimeter and it was at 0% .
I decided to swap out the control module a 2nd time with the original fan module from my original OEM fan assembly (I never threw it out when I replaced it with the TYC 621870 fan assembly).
The original OEM fan control module worked like a charm.
I had been considering buying a OEM fan control module from the dealership prior to realizing I could test with my original fan assembly's control module. In the process I discovered that it was only $20 more than the aftermarket piece ($80 vs $60).
I will go with OEM from the dealership from now on and would encourage others to do the same.

[Ilya]

Glad you got it sorted! I too prefer OEM (within reason) 9 times out of 10.

[bicsintegra]

i have had the same experience with my m35 and my f150, cheap parts cost me time, frustration, and even more money. I buy all of my parts from the dealership or tascaparts online. never buy any spark plugs or coil over plugs from Ebay they got me twice.

[EdBwoy]

Thank you for this sobering reminder.

With the coolant system, I have learned to stick to OEM components - radiator cap, thermostat, fan module...